Bumping this up for a quick question.
Original question is asking whether jkmn = 1.
I rephrased to: does jk = 1/(mn) by dividing both sides by mn
Statement 1: jk/mn = 1 --> rephrase to jk = mn
Since jk = mn and does not equal 1/mn, I said this was sufficient.
Statement 2: j = 1/k; m = 1/n --> rephrase to jk = 1 and mn = 1
I chose answer choice D while the OA is B. Can someone please explain where I went wrong?
jk = mn and jk = 1/mn does not exclude each other.Does the product JKMN = 1?
(1) (JK)/(MN) = 1 --> JK=MN. The question becomes: does (MN)^2=1. We don't know that. Not sufficient.
(2) J= (1/K) and M = (1/N) --> JKMN = 1/K*K*1/N*N = 1. Sufficient.
Thanks Bunuel, I understand now.
Is there a way to not fall into these types of traps? Working under time pressure, I saw that jk = 1/mn and assumed immediately that jk = mn would mean sufficient (since the answer would be "no" jkmn=/=1), forgetting that if mn = 1, it would actually be insufficient (since the answer would be "sometimes yes and sometimes no").
Is there a concept that I'm missing or is this more about working on fundamentals?